Ok thanks, so my 300w of osram cobs not to far off a 600w hps then, has anyone used a r&b led panel combined with white cobs and would it be worth while? As have a grownorthern ms0006 I could throw in the mix?I'd say at current efficiency levels, 60watts of LED for every 100 watts of HPS/MH. The flexibility of COB tech makes them much more adapable to multiple situations/garden layouts, plus you can run the hard or soft, or anywhere in between You can build a light to get started, run it hard, then add more cobs and lower the power per cob,as time and money allows to improve efficiency.